120 
solution of citric acid.<* If the paper can take up the acid from the root surface, 
surely the much stronger capillary action of the soil can do so, according to Came- 
ron's experiment quoted on page 54 of Bulletin 22. h But if so, Whitney's entire 
argument based on watery-soil solutions falls to the ground. 
Not the least remarkable part of the bulletin is that in which Whitney discusses 
the use and action of fertilizers. He does admit that "there is no question that in 
certain cases, and in many eases, the application of commercial fertilizers is bene- 
ficial to the crop." But he calmly brushes aside as so many cobwebs the enormously 
cumulative evidence of all the practical experience of three-quarters of a century in 
the use of commercial fertilizers, as well as the carefully guarded culture experiments 
made during that time by numerous scientific workers, and announces the truism 
that climatic and seasonal conditions may neutralize the beneficial effects of any and 
all fertilizers used. This has been often said, experienced, and foreseen. Everyone 
knows that deficiency of moisture or heat, or imperfect cultivation, as well as the 
improper manner of application of fertilizers, will render them wholly ineffective. 
We have also long known that soluble fertilizers soon become insoluble ( but not 
necessarily unavailable) in the soil, in a manner fairly well understood, and that 
hence they can not long influence the w 7 atery-soil solution to which Whitney pins 
his faith. But since the same conditions influence the unfertilized soils to even a 
greater degree, manifestly because of the slower and less vigorous development of the 
plants, it is not easy to see what special corroboration Whitney's hypothesis can 
derive therefrom. He calmly discards, as having been made under "abnormal con- 
ditions," the elaborate and conclusive experiments made by the best observers in 
pot culture, in which the physical factors were so controlled as to eliminate them 
from the problem of the action of special fertilizers, and we are told that "very little 
effect is obtained in field culture in attempts to increase the value of crops showing 
inferior growth by the application of fertilizers." Atrip through the malodorous 
turnip fields of the low countries of Switzerland in autumn would convince even the 
Bureau that the thrifty inhabitants know that when fertilizer is made to reach the 
feeding roots its action is invariably most strikingly beneficial. That a top-dressing 
of soluble fertilizers on a growing crop can do but little good needs no discussion; 
and it is but too true that a great deal of the fertilizers used in the arid region remains 
wholly ineffective for a long time because of the deep range of the feeding roots and 
the shallow application of insoluble fertilizers. 
In the classic water-culture experiments of Birner and Lucanus, quoted in the bul- 
letin (p. 15), the well water was supplied continuously and in different amounts. It 
is thus no wonder that the results were so good, for at no time was there a lack of 
food supply, nor would such changes as would injuriously affect the growth occur. 
But for these frequent renewals of water the result would doubtless have been very 
different, if only as a consequence of changes in the reaction of the solution. It is 
singular that this important point is not even casually mentioned in the bulletin with 
respect to the soil solutions. The deleterious effect of the soil acidity upon most cul- 
ture plants, long known in general, has been w T ell and thoroughly investigated by 
H. J. Wheeler. Yet neither in the tables nor in the text of this bulletin do we find 
any evidence that this point has had any attention with respect to its possible bear- 
ings on the differences in production on what are held by the Bureau to be identical 
soil areas. We are not informed whether the large amounts of lime present in some 
of these solutions were sulphate or carbonate; yet the importance of this difference 
is enormous, as is well shown by the contrasts between the natural vegetation as well 
as the cultural value of gypseous as against limestone lands, which are everywhere 
among the most productive. An excellent illustration of what this omission may 
mean exists on the Gulf coast of Mississippi, where (as I have shown in the Report 
on Cotton Culture, Tenth Census, vol. 5, p. 69) the soil of the infertile "sand ham- 
mocks" differs from the highly and lastingly productive soil of the "shell hammocks" 
almost alone in the proportion of lime (calcic and carbonate) and phosphoric acid 
present, and in having an acid reaction; the percentages of plant food being very low 
in both and both equally of great depth. This observation, together with others, 
led me very early (I860) to the conclusion that mere percentages of plant food were 
not in all cases proper criteria of soil fertility, and also to the enunciation of the state- 
's California Sta. Rpt. 1896-97, p. 181. 
&"When a porous cell, having deposited in it a semipermeable membrane through 
which water can pass freely, but through which salts and certain organic substances 
like sugar can not pass readily, is buried in a soil short of saturation, but yet in fair 
condition for plant growth, the soil will draw water from the cell against a calculated 
osmotic pressure in the cell of thirty-six atmospheres, or about 500 pounds per square 
inch." 
